At least nine people died and 48 were injured in a deliberate explosion during a dispute over coal mine resources in southwestern Yunnan Province, local authorities said Friday.

The explosion occurred at around 9 a.m. Thursday at the Xiaosongdi coal mine in Luxi county, of Honghe Hani and Yi Autonomous Prefecture, according to the local publicity department.

Five people were critically ill but stable and 19 had been discharged from hospital by Friday afternoon, officials at the county public security bureau said.

The contractors of Xiaosongdi mine and Yuejin coal mine, which are close to each other, had a dispute over coal resources after the underground shaft of one mine broke through into the other.

Scores of people hired by Zheng Chunyun, owner of the Yuejin mine, arrived at Xiaosongdi mine in more than 10 cars and minibuses, local villagers and police said.

"We got ambushed with an explosion," said one of the injured. "All the dead and injured were from our side."

Zheng and Wang Jianfu, contractor of the Xiaosongdi coal mine, are in police custody.

No further details are immediately available.

Police are still investigating the case.